Automatic air diffuser and regulator

ABSTRACT

A device is provided for regulating and diffusing fresh air introduced into rooms, notably rooms of dwellings and the device comprises a resilient strip positioned across a fresh air passage in an outer wall. The resilient strip is responsive to air pressure differential generated in the passage and the strip has one edge fastened to the wall of the passage and a free edge remote from the fastened edge with lugs formed at spaced intervals along the free edge adapted to slidably engage a surface lining in the wall. A set of fixed blades for diffusing the incoming airstream are mounted in the passage end having leading edges disposed adjacent the fastened edge and shaped to constitute a bearing support for modifying the curvature of the strip according to the pressure differential acting upon said strip and thus cause the incoming airstream to have a substantial input in spite of wide variations in the incoming airstream.

United States Patent J ardinier et al.

[54] AUTOMATIC AIR DIFFUSER AND REGULATOR [72] Inventors: Pierre Jardinier, Gournay sur Marne;

Jack Simonnot, Lesigny, both of France [73] Assignee: ALDES Ateliers Lyonnais dEmboutissage Special (Soclete Anonyme), Lyon, France [22] Filed: Aug. 13, 1970 [21] Appl. No.: 63,554

[ 1 Feb. 15,1972

3,468,239 9/1969 De Hart et al. ..98/121 X Primary ExaminerEdward J. Michael AttorneyWaters, Roditi, Schwartz & Nissen [57] ABSTRACT A device is provided for regulating and diffusing fresh air introduced into rooms, notably rooms of dwellings and the device comprises a resilient strip positioned across a fresh air passage in an outer wall. The resilient strip is responsive to air pressure differential generated in the passage and the strip has one edge fastened to the wall of the passage and a free edge remote from the fastened edge with lugs formed at spaced intervals along the free edge adapted to slidably engage a surface lining in the wall. A set of fixed blades for diffusing the incoming airstream are mounted in the passage end having leading edges disposed adjacent the fastened edge and shaped to constitute a bearing support for modifying the curvature of the strip according to the pressure differential acting upon said strip and thus cause the incoming airstream to have a substantial input in spite of wide variations in the incoming airstream AUTOMATIC AIR DIFFUSER AND REGULATOR BACKGROUND OF THE INVENTION This invention relates to an air input diffuser and regulator adapted to be fitted across an air inlet passage or aperture formed in an outer wall of a room to be ventilated.

Devices adapted to maintain at a substantially constant rate the air input delivered into a room, irrespective of the pressure exerted by the air on its walls, are already known in the art.

However, these known devices, due to rapid fluctuations in the air speed and/or orientation, are frequently the cause of oscillatory effects generating noise detrimental to the comfort of the occupants of the rooms equipped with such devices. In fact, some of these devices comprise essentially a shutter rigid with a shaft and adapted, in the case of pressure differential, to reduce the free passage area through a duct or casing, the shutter being normally urged to a predetermined position, in order to maintain a substantially constant air input, by a torque applied to the shaft of said shutter. When the air pressure changes very rapidly, this shutter, due to its inertia, will strike the inner wall of the duct or casing and oscillate for a relatively long time before resuming its condition of equilibrium; therefore, the air input regulation is undesirable and the shock and bearing sounds thus produced are unpleasant to the occupants of the rooms in which these diffusers are fitted.

Other known apparatus comprises a sheet or flap of resilient material rigidly fastened along one side and adapted to bend freely under the influence of a pressure differential, thus causing a corresponding variation in the cross-sectional passage area in a duct, in order to maintain a constant-input airstream therein. This resilient sheet, due to the action exerted thereon by the airstream, may also become a source of vibration similar to that produced in the reeds of wind instruments and thus generate undesired noise.

SUMMARY OF THE INVENTION lt is the essential object of the present invention to avoid these inconveniences associated with the known devices of this type. This invention is concerned primarily with an automatic air input difl'user and regulator responsive to a variable negative or positive pressure, and comprising essentially:

fixed diffusion blades disposed across the air passage,

a resilient strip fastened transversely along one of its major edges for adjusting, under the influence of the airstream, the cross-sectional passage area available to the airstream by elastic deformation of said strip, the resiliency of which is adapted to counteract the effects of the airstream and to constantly urge the strip to its open position.

According to a first feature characterizing this invention, the leading edges of the fixed diffusion blades together constitute a suitably shaped bearing support engageable by a portion of the resilient strip responsive to the pressure of the airstream; the contour of the blades being such as to impose a predetermined deformation on the strip subject to variable air pressures such that the air throughput in the remaining free cross-sectional passage area remains substantially constant.

According to another feature characterizing this invention, one or more free edges of said strip are formed with at least one lug the free end of which is adapted, under the influence of a predetermined air pressure differential to engage a surface, and to slide on said surface as a consequence of elastic deformation of said strip from pressure differences greater than said predetermined air pressure differential. It was found that the sliding engagement between said lugs and the corresponding surface, as a consequence of a resilient deformation of said strip due to the dynamic action exerted thereon by the incoming airstream, is sufl'icient for preventing said strip from becoming asource of vibratory phenomena within the normal range of values assumed by the angle of attack formed between said airstream and the free edges of said strip. In addition, in a specific form of embodiment of the device of this invention, which comprises a relatively great number of lugs formed along the major free edge of the strip opposite the fixed edge thereof, when an airstream corresponding to a relatively great pressure differential is applied in the passage, said lugs produce transverse distortions of said free edges so as to preserve openings adjacent said lugs, at spaced intervals, in said passage. Thus, a good closing sensitivity of the strip and a convenient distribution of an airstream across a relatively great width can be obtained even with relatively small variations in the pressure differentials.

The thickness and composition of the resilient strip and the dimensions and relative spacing of the lugs are a function of the dimensions of the ventilation duct or passage, and also of the pressure difi'erentials likely to prevail on either side of this duct or passage.

In a preferred embodiment of the present invention, which is both simple and economical, the resilient strip mounted across the passage is of substantially rectangular configuration and has its free major edge formed with relatively wide notches forming the lugs therebetween, this strip being obtained by cutting a plastic sheet whose elasticity and thickness are consistent with the characteristics of the air or ventilation passage to provide a predetennined air input under pressure difl'erentials lying within a predetermined range.

A clearer understanding of the present invention will be had from the following description of a few illustrative embodiments thereof given by way of example and shown diagrammatically in the attached drawing, in which:

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a cross-sectional view of an airstream input stabilizing device according to invention;

FIG. 2 is a plan view of the stabilizing device in FIG. 1;

FIGS. 3 and 4 are sectional views similar to FIG. I for facilitating the understanding of the mode of operation of the device, and

FIG. 5 is a cross-sectional view of a modified embodiment of the device of FIGS. 1 and 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Referring to FIGS. I and 2, therein the device according to this invention comprises a base plate I of rectangular configuration, of which the two side edges are rigid with the edges of a pair of parallel and identical lateral plates 2d and 2g.

The end portions of the edges of sideplates 2d and 23 which are opposite to base plate I are also rigid with a crossmember 3 extending parallel to the edges of baseplate l and connected at spaced intervals through deflector blades 4 to base plate I.

The leading edges 5 of the blades 4 are all identical and aligned parallel to the baseplate l and crossmember 3.

Moreover; the crossmember 3 has a flat inclined face directed towards the free edge of baseplate 1, and the convex leading edges of blades 4 are connected tangentially to this face of crossmember 3. Moreover, the crossmember 3 carries studs engageable in corresponding holes formed in a flat bar 6, so as to constitute a pair of jaws for mounting a flat strip 7 therebetween.

The free edge of strip 7, i.e., the edge opposite the one clamped between jaws 3, 6, is formed with rectangular lugs 8.

Two of the lugs 8 are formed at the ends of the strip and the other lugs are disposed at spaced intervals therebetween.

The width, denoted 1,, of strip 7, which corresponds to the distance measured between the longitudinal edge clamped between the jaws 3, 6 and the opposite edge carrying the lugs 8, corresponds approximately to the curvilinear length of the convex leading edge of each blade 4.

The strip 7 provided with the lugs 8 may be obtained by cutting a relatively thin sheet (for example a sheet having a thickness of the order of 0.75 mm.) of ethylene polyterephthalate, a substance characterized by good flexibility but also by a rigidity sufficient to remain flat when subjected to stress resulting from its inherent weight, in any position in relation to a horizontal plane.

The length 1 of each lug 8 and the inclination of crossmember 3 in relation to baseplate I are chosen to cause the free edges of the lugs to normally extend a short distance above the upper face of baseplate 1.

Now the operation of the above-described device will be explained with reference to FIGS. 1 3 and 4 of the drawings.

A pressure differential ga -p produced on either side of a wall equipped with this device will cause flow of an airstream in the direction of the arrows f, and f tending to press the strip 7 against the leading edges 5 of blades 4.

Above a value Ap of this pressure differential p-p equal to p and depending on the nature and thickness of strip 7, the action of the airstream is sufficient to overcome the resistance to flexure of this strip which thus becomes curved and bears against the leading edges 5 of blades 4, this distortion being accompanied by a reduction in the cross-sectional passage area available for the airstream between the free edge of strip 7 and baseplate 1.

Under these conditions, it is clear than any increment in this pressure differential above the aforementioned value Ap will tend to close the passage and thus reduce the cross-sectional area thereof, and that conversely any decrease in this pressure differential will enable the inherent elasticity of strip 7 to restore the latter to its initial, inoperative position to open the passage and thus increase the cross-sectional area thereof, whereby the air input rate is stabilized to a predetermined value.

With a value of Ap greater than Ap of the pressure differential pp the free ends of lugs 8 engage the baseplate 1. The value Ap, is slightly lower than the value of the pressure differential pp"' at which the angle of attack of the airstream against the free edge of the elastic strip 7 without any lugs 8 will start the generation of vibratory effects in this strip.

lt is thus possible, by taking due consideration of the strip inclination due to this pressure differential Ap to provide a length I: of the lugs 8 necessary for causing their free edges to engage the baseplate 1 under the influence of the pressure differential Ap and therefore avoid any vibratory phenomena in this strip when the pressure differential attains a critical value slightly greater than A12 When the pressure differential p'-p is relatively high, the flexure of lugs 8 engaging baseplate 1 will prevent the adjacent portions of the free edge of strip 7 from contacting this baseplate 1, thus preserving on either side of each lug, at spaced intervals, the presence of openings corresponding substantially to the desired airstream throughput. Moreover, this ensures a better response of the strip 7 when a device according to this invention is provided for regulating the entry of a relatively moderate air input distributed along a great length under pressures varying through a wide range of values.

In FIG. 5 the lugs 8 engage a deflecting wall 9 producing a change substantially at right angles in the direction of flow of the incoming airstream in order to orient the latter and avoid disturbing effect.

It may also be noted that the shape and inclination of the contact surfaces in relation to the lugs 8 must be such as to permit the sliding engagement between these lugs and the surfaces and prevent any jamming of the free ends of the lugs which might lock them.

What is claimed is:

1. An automatic air input regulator and diffuser adapted for controlling the delivery of fresh air through an air passage into a room, said regulator and diffuser comprising diffusion blades cooperatively constitute a support for said strip upon deformation of the strip by the pressure of the airstream, said leading edges having a predetermined contour to impose a predetermined elastic deformation on the strip responsive to variable air pressures so that the airflow in the free passage remains substantially constant, at least said resilient strip, comprising at least one flexible resilient lug at the other of said edges thereof adapted, under the influence of a predetermined pressure difierential to contact a wall of the air passage and to slide on said wall due to deformation of the strip caused by pressure differentials greater than said, predetermined pressure differential.

2. An automatic air input regulator and diffuser as claimed in claim 1, wherein the length of said strip and the number of said lugs is such as to provide substantially uniform distribution of the airstream across a relatively great width under relatively high-differential pressure values.

3. An automatic air input regulator and diffuser as claimed in claim 1, wherein said strip has a substantially rectangular configuration with notches provided along said other edge to provide a plurality of said lugs at transverse spaced locations.

4. An automatic air input regulator and diffuser as claimed in claim 1 comprising a baseplate in said passage facing said lug for slidable passage of the lug thereon, said lug being initially spaced from said baseplate in said open position of said strip.

5. An automatic air input regulator and diffuser as claimed in claim 4, wherein said strip is relatively thin and is constituted by a plastic material having a relatively great resistance to flexure.

6. An automatic air input regulator and diffuser as claimed in claim 1 comprising jaw means secured in said air passage and clamping said strip at said one edge thereof.

7. An automatic air input regulator and diffuser as claimed in claim 6 wherein said jaw means comprises a crossmember engaging said strip and securely fastened to said blades.

8. An automatic air input regulator and diffuser as claimed in claim 7 comprising a baseplate secured to said blades and mounted in said air passage for slidable passage of said lug thereon.

9. An automatic air input regulator and diffuser as claimed in claim 8 wherein said leading edges of the blades are of convex shape and said strip is initially planar and undergoes bending deformation to conform to the convex shape of the blades under pressure differentials greater than said predetermined pressure differential.

10. An automatic air input regulator and diffuser as claimed in claim 9 wherein said strip is initially supported in an inclined depending attitude in said passage upstream of the blades.

11. An automatic air input regulator and diffuser as claimed in claim 10 wherein said blades, strip and baseplate are secured together as a unitary assembly. 

1. An automatic air input regulator and diffuser adapted for controlling the delivery of fresh air through an air passage into a room, said regulator and diffuser comprising diffusion blades disposed across the air passage, a resilient strip extending transversely of said air passage and having opposite edges, said strip being supported by one of its edges to project into the air passage for adjusting under the control of the incoming airstream the cross-sectional area available in said passage by elastic deformation of said strip, said strip having an inherent elasticity capable of resisting the action of said airstream while constantly urging said strip to an open position for the airstream, said diffusion blades having leading edges which cooperatively constitute a support for said strip upon deformation of the strip by the pressure of the airstream, said leading edges having a predetermined contour to impose a predetermined elastic deformation on the strip responsive to variable air pressures so that the airflow in the free passage remains substantially constant, at least said resilient strip, comprising at least one flexible resilient lug at the other of said edges thereof adapted, under the influence of a predetermined pressure differential to contact a wall of the air passage and to slide on said wall due to deformation of the strip caused by pressure differentials greater than said predetermined pressure differential.
 2. An automatic air input regulator and diffuser as claimed in claim 1, wherein the length of said strip and the number of said lugs is such as to provide substantially uniform distribution of the airstream across a relatively great width under relatively high-differential pressure values.
 3. An automatic air input regulator and diffuser as claimed in claim 1, wherein said strip has a substantially rectangular configuration with notches provided along said other edge to provide a plurality of said lugs at transverse spaced locations.
 4. An automatic air input regulator and diffuser as claimed in claim 1 comprising a baseplate in said passage facing said lug for slidable passage of the lug thereon, said lug being initially spaced from said baseplate in said open position of said strip.
 5. An automatic air input regulator and diffuser as claimed in claim 4, wherein said strip is relatively thin and is constituted by a plastic material having a relatively great resistance to flexure.
 6. An automatic air input regulator and diffuser as claimed in claim 1 comprising jaw means secured in said air passage and clamping said strip at said one edge thereof.
 7. An automatic air input regulator and diffuser as claimed in claim 6 wherein said jaw means comprises a crossmember engaging said strip and securely fastened to said blades.
 8. An automatic air input regulator and diffuser as claimed in claim 7 comprising a baseplate secured to said blades and mounted in said air passage for slidable passage of said lug thereon.
 9. An automatic air input regulator and diffuser as claimed in claim 8 wherein said leading edges of the blades are of convex shape and said strip is initially planar and undergoes bending deformation to conform to the convex shape of the blades under pressure differentials greater than said predetermined pressure differential.
 10. An automatic air input regulator and diffuser as claimed in claim 9 wherein said strip is initially supported in an inclined depending attitude in said passage upstream of the blades.
 11. An automatic air input regulator and diffuser as claimed in claim 10 wherein said blades, strip and baseplate are secured together as a unitary assembly. 